Modern capture solutions are digital, so you'll need a way to digitise the output of your 286 or 386.

I use an OSSC and a Magewell Pro Capture 4k HDMI, and have no issues capturing anything, be it 70hz or weird resolutions. It's an expensive solution, but previous Magewell cards would work the same, you can find them second hand for 100 bucks or so, and offer up to 1920x1200@60hz without much hassle (I replaced my original Quad Pro Capture because I was moving to 1440p). Of course, at that point, you can also simply purchase a VGA capture card.

For earlier graphics adapters you'll need something that converts them into something else, like Serdashop's MCE2VGA for Hercules, EGA, CGA and MDA.

Don't those Blackmagic cards still support analog video? They're not cheap though.

Don't know how well it would work, but I was thinking of trying to use a VGA to HDMI and a HDMI USB capture device to try and record VGA - not sure it would like the BIOS mode though, I think that can be a funny resolution

Doornkaat wrote on 2022-02-15, 17:07:

Don't those Blackmagic cards still support analog video? They're not cheap though.

I think I might have read somewhere that those Blackmagic cards don't like non ATSC/HDTV resolution very much, but I could be wrong .

These two threads cover what OP is looking for and more . I would stick to the posts from 2019 onward for currently available options .

What are the best Vga to hdmi scalers or peripherals for MS-DOS games ?
VGA Capture Thread

I can recommend 2nd hand pro video equipment from a company called Kramer. You can buy their scalers for low money on ebay or local platforms. As an example Kramer VP719 ; VP721; VP724 etc. (starting at 20€ in my area) I think this is a great solution to capture old VGA stuff. You can input VGA (and other interfaces depending on the model) in any resolution / refresh rate and the unit always will translate this to your resolution of choice, 1024*786/60Hz as an example. Most units have two VGA outputs so you can put your monitor on one and the capture device (cheap VGA to HDMI and then cheap HDMI to USB will do fine) on the 2nd output. This Kramer-units are very reliable and well-made so you don't need to worry it's 2nd hand I think.

Matth79 wrote on 2022-02-16, 00:44:

Don't know how well it would work, but I was thinking of trying to use a VGA to HDMI and a HDMI USB capture device to try and record VGA - not sure it would like the BIOS mode though, I think that can be a funny resolution

I think that will be hit or miss.
Most of them do not work with the low resolution Text-Mode/BIOS screen, and also don't work properly with 70Hz. (60Hz only).

OSSC with a Camlink 4K or a Datapath E1S should work fine for that.

Extron RGB DVI or HDMI 300 with practically any HDMI capture card should work fine too.

I've had no issues capturing BIOS & POST screens with an Extron RGB-DVI 300, and more recently an Epiphan DVI2USB 3.0. I even had success with one of the $12 cheapies pictured below, but buyer beware as the internals can vary and not everyone gets the same results.